Investigations on Creep Strength Design Criteria for High Temperature Components on the Base of Creep Cavity Theory

Creep failure mechanisms of high temperature components under multiaxial stress states are analyzed,and the design criteria for creep strain and stress are presented on the basis of cavity growth theory.Methods of how to calculate creep equivalent stress and strain and how to determine permissible creep stress and strain are proposed.Compared with the traditional creep design approach based on classic plastic theory,the proposed method in this paper takes into account the physical mechanism of creep failure and therefore can predict multiaxial creep behavior of high temperature components more reasonably.In the end,difficulties faced in the field of multiaxial creep strength design are analyzed and recommendations for further research are presented.